Tamilnadu Hydrology Project-II

Chief Engineer, WRD State Ground & Surface Water Resources Data Centre,

Chennai-600113

DSS(Planning) for IWRD

By

SGSWRDC, TNWRD, Chennai

About SG&SWRDC

Custodian of Groundwater resources of Tamilnadu.

Assess and categorize the GW potential of the State.

Support the government in the policy matters and governance of

groundwater.

Repository of Hydrological, Hydro-meteorological , Hydro-

geological and Water Quality data.

Implemented the Hydrology Project-I and established the data

collection system.

Implements the Hydrology Project-II and develops DSS for 3

river basins and Hydrological Design Aids for balance basins

of Tamilnadu.

Synopsis on Hydrology Project-I

• Implemented during 1995 – 2003 at a cost of Rs 57.37 crore.

• Objective is to establish a Hydrological Information System (HIS) in

Tamilnadu among other States.

S.No Assets created Nos

1 Rainfall Stations (daily) 213

2 Rainfall Stations (Hourly) 57

3 Climatic Stations (manual) 45

4 Climatic Stations (automatic) 6

5 Stream flow stations 112

6 Piezometers 852

7 Water Quality (SW) 71

8 Water Quality (GW) 2074

9 Laboratories 1+3

• The HIS is well institutionalized in SG&SWRDC.

DSS Overview

Before DSS - Tank -Dry After DSS- Tank –Water Plenty

Objective of DSS

Dynamic Water budgeting at river basin scale.

To assess the spatial and temporal distribution of

Surfacewater and groundwater in the State.

Use the Water Balance information for IWRM in the

basin.

Institutionalize and sustain the DSS in the State.

Technological backing for the SWARMA.

Concept of DSS

• Integrated Water Resources Management (IWRM) covering the

following modules in the DSS (Planning) of each Basin.

Surface water Planning

Drought Management

Conjunctive use of Ground & Surface water

Reservoir Operation

Water Quality

Benefits of Decision Support System

Spatial & Temporal Assessment of Surface Water and Groundwater

in the river basin.

Judicious planning and allotment of SW and GW for a predicted

monsoon, year, decade.

Scenario Analysis of adopting different Cropping pattern and their

impact on the SW and GW resources.

Identification of sites fit for Artificial Recharge Schemes and

quantification of their impact on the Groundwater augmentation.

Spatial & Temporal distribution of WQ across the basin.

Collaborative Decision making by all stakeholders in a river basin.

Kind of DSS that the State requires

Gives the spatial and temporal water balance (SW+GW) of a

basin.

Based on a distributed 3D Hydrological model of the basin.

Take into account of the tank system on the hydrology of the

basin.

Dynamic and at daily time steps.

Simulates the SW and GW and validate them against the

observed catchment outflow and piezometric heads.

Web-enabled.

User-friendly and supports the SWARMA

Data Availability –

Readily Available

Timeseries

Rainfall (daily),

Rainfall (hourly),

Eto(daily),

GWL (monthly),

Water Quality(bi-annual)

Static

Lithology,

Cartosat-1 stereo imageries.

Basin Boundaries.

Geology maps.

Geomorphology maps.

Soil maps.

Data Availability –

Secondary data to be collected

Timeseries

Cropping pattern under

irrigation tanks and

river/canal sluices (Fasli)

Tank filling details

Reservoir

(inflow,storage,outflow)

GW abstraction from TWAD

and Industrial wells.

Static

DEM from Cartosat-1 stereo

imageries.

Location of TWAD and

Industrial wells.

Data Availability –

Primary data to be collected

Command Area maps under tanks and river/canal sluices.

Ground Control Points to calibrate the DEMs.

River/ canal Cross-sections.

Tank FTLs and Sluice levels.

Sill levels of River/Canal sluices.

Drainage network of Supply channels from weirs and surplus

courses of tanks.

Implementation Strategy

Agreement on the Tamilnadu DSS Framework.

Agreement on the modeling code and databases to be used for

the future DSSs.

Identification of basins among the agencies.

Counterparts personnel for the identified basins

between IWS + SG&SWRDC + Consultancy + PF + Regions.

Training for the Counterpart Personnel on modelling.

Vaippar

Tamiraparani Basin

Agniar Basin

Integrated Water Resources

Management (IWRM), covering SW,

GW & WQ in 3 Basins.

Basins for DSS

Present Status of DSS Goals Component Status

Goal1 For a given Monsoon

prediction, which part of

the basin can go in for

Wet/Dry crop?

1. Basin is divided into Subbasins.

2. Methodology has been evolved to populate subbasins in DSS Software with SW &

GW availability obtained from MikeSHE and MikeBasin.

3. For a given Monsoon prediction, recommended subbasins for Wet/ Dry crop will

be shown as a GIS Map.

Goal2 How much for different

sectors? How much from

SW and how much from

GW and when?

1. MikeSHE model is being set up.

2. Methodology to assess available SW & GW as a time series has been evolved.

3. Upon calibration of the models, allocation for different sectors will be assessed.

Goal3 Shall we invest in Artificial

Recharge Structures in a

particular location of the

basin? What are the

impacts on GW and SW?

1. MikeSHE model is being set up.

2. It has complete lithology and topsoil GIS Maps.

3. Upon calibration, the model will show the sites fit for ARS and impact on both the

GW & SW.

Goal4 Whether to grant a

Groundwater abstraction

permit? How much?

1. MikeSHE model is being set up.

2. All existing abstraction wells are there in the model.

3. Upon Calibration, the new abstraction well with its demand will be simulated in the

model.

4. The output will show the feasibility of issuing the abstraction permits.

Architecture of Tamilnadu DSS

Level 1

Level 2

Level 3

Administrator (1)

SG&SWRDC (5) / SWaRMA (10)

Privileges

INPUT

Add/Edit data to

selected tables,

Feedback

WRD (100)

TWAD (50)

Agri (50)

Industries ( 50)

Collectors (32)

Tahsildars ( 215)

WUA (4100 + 8000)

+

RTDAS

CM (1)

Ministers (30)

Secretaries (30)

Chief Engineers (30)

+

Public (no limit)

OUTPUT

View MikeSHE results,

Run Mike Basin

Simulations

INPUT

Feedback

OUTPUT

View and download

Data

Text/Graphic/ Map

Reports (PDF),

for different users levels.

Stakeholders

INPUT

Control

Administration

Back-up

Recovery

Improvement

Output

Feedback

Hired Web/Database Server

Operational Structure of DSS

RDBMS

Internet / WAN Internet Server

WRD Agri Revenue

Policy makers Technocrats Farmers

State

Water

Authority

HDA DSS

Basin Info System

in GIS

Public

Drinking

Input Data

Output Reports

Industry

Data

Sharing

Towards a Multi-criteria Collaborative Decision Making in Water Resources Management in a River basin

Hydrological Models & DSS in Tamilnadu

Mike Basin

DSS Solution Software

MikeSHE

GW

(R

ech

arg

e/ A

va

ilab

ility

)

SW

(R

ive

r F

low

)

SW

(Tan

ks/ D

ete

ntio

n S

tora

ge

)

Pre Defined Scenario Outputs

Database with all GIS, TS, Results

Technology developed by DHI, now under testing

Technology developed by DHI, now under testing

Technology developed by DHI, now under testing

Technology developed by DHI, now under testing

Non Command Area digitization

DSS Progress - Vaippar

Command Areas under each Tank

DSS Progress - Tamiraparani

DSS Progress - Agniar

Why Decision Support System?

2004 2005 2006

2007 2008 2009

IMD Predicts an Above

or Below Normal

North-East

Monsoon!

How DSS can

help us?

2010

Conclusion

The Decision Support System, on its completion, will be

the Technological backing for the State Water Resources

Management Authority (SWaRMA).

It will way for better water resources management at

river basin framework.

Thokkalikadu Weir

THANK YOU